This particular invention generally relates to the expansion of tobacco for purposes of increasing its filling capacity. Specifically, it pertains to a novel and improved apparatus which rapidly, economically, simply, and reliably expands a total blend of tobacco to the extent that the entire blend may be used in the fabrication of complete rod-like tobacco products, such that the expanded tobacco resists the tendency to close back, possesses the structural characteristic of non-collapsibility, and does not contain materials unnatural to tobacco.
Presently, in the tobacco industry various techniques exist for puffing tobacco so as to obtain a greater filling capacity therefor. What essentially occurs in a typical puffing operation is that the normally compressed and dried tobacco is dimensionally expanded to a certain extent such that it is somewhat restored to the dimension it had prior to the standard drying and cutting procedures.
Generally speaking, a major disadvantage associated with heretofore known puffing techniques is the degree of expansion which frequently results. In particular, the foregoing type of expansion is of such a relatively large magnitude that in the event an entire blend or batch of shredded and/or artificially treated tobacco is exposed to such conventional processes and subsequently utilized to form the standard types of rod-like tobacco end products, such as cigarettes or the like, it suffers from the shortcoming that the tobacco end product is relatively easily collapsible. Such collapsibility will correspondingly result in end products which lack firmness and are otherwise of lower quality. Quite obviously, such tobacco end products as cigarettes and the like made exclusively of this expanded tobacco would tend to be undesirable for typical purposes of commercially marketing the same.
Accordingly, to obviate the previously mentioned disadvantages, it has become a rather customary and accepted industry practice to admix only a partial amount of the expanded tobacco with the usual non-expanded tobacco. The resulting admixture results in a compromise which provides rod-like tobacco products at least partially formed from puffed tobacco which has sufficient structural rigidity in customary usage. However, such processes nonetheless fail to completely and satisfactorily enable a total blend of tobacco to be used exclusively in forming firm and commercially acceptable tobacco end products. Moreover, by reason of the fact that expanded and non-expanded tobacco must be admixed, additional drawbacks result. For instance, an extra blending step is required, as well as the requirement for separate storage facilities to conveniently store the expanded and non-expanded tobacco. The additional blending step and separate storage facilities, of course, result in increased costs.
Apart from the foregoing commented upon shortcomings in known prior art expansion processes, some of such processes typically rely upon undesirable artificial chemical solvents to achieve puffing. The use of artificial chemical solvents normally results in a tendency to leave non-tobacco elements with the tobacco. Moreover, aside from the aforementioned disadvantages, undesirable artificial chemical solvents add to the overall cost factors in producing tobacco end products.
In connection with the traditional drying apparatus used in the field for drying tobacco, many require considerable periods of time to effectuate an adequate drying operation. Therefore, they result in additional operational time and costs which further detract from any economic savings which might otherwise be possible with quicker drying modes of operation. Furthermore, there is tendency for mechanical abuse to occur to the tobacco in these known tobacco dryers. Mechanical abuse contributes to the break-up of tobacco which correspondingly results in a less satisfactory final product.
In view of the foregoing comments directed to the various known prior art forms of apparatus and methods for purposes of increasing the filling capacity of tobacco, it will be appreciated that the prior art cannot achieve, in a simple, reliable, rapid and economical manner, the expansion of tobacco materials, and particularly a total blend of tobacco, such that the expanded tobacco can be exclusively employed for the fabrication of conventional rod-like tobacco products which have the firmness necessary for ordinary use. In addition, such conventional techniques are relatively expensive since they utilize non-expanded tobacco to obtain a suitable structurally rigid rod-like product and sometimes rely upon non-tobacco elements.